Form tie for wall structures



Nov. 14, 1933.

Filed Feb. 23, 1931 (ili Patented Nov.. 14, 1933 FOEM TIE FOB WALL STRUCTUEES Lawrcnce H. Unabach, Chicago, lil-ll assignor to Universal Form Clamp Co., Chicago, Ill., a.

corporaticn of Illinois Application February 23, 1931. Serial No. 511646 2 Claims.

' in order that the finished concrete may assume the desired shape.

Form ties for wall structures usually include an intermediate tie rod and a pair of end bolts alined axially and detachably connected together by coupling nuts of various knds. The intermediate tie rod is arranged so as to extend between the side members of the' form and is left embedded in the concrete after the form is dis- 'mantled The end bolts are usually provided with clamping means at their extrernities for securingthe form against spreading, and after the concrete has set, the end bolts and couplings are removed, when the forms are dismantled.

"` The couplings are usually threaded on the ends of the intermediate tie rod.'

Considerable difficulty has been experienced in re'n'vng the couplings after the concrete has set because the concrete, while hardening, exerts a great deal of pressure on the' couplings and tends to bind them to the tie rod. It is, therefore, desirable to slightly loosen the coupling from the concrete by partially un'screwing it before the concrete has completely set and before the forms are dismantled. With the common type of form tie heretofore in use, any loosening of the couplings would expand the form tie with the result that the form sides would be spread apart.

The main objects of ?this invention are to provide a form tie having an improved form of coupling; to. provide an 'improved form of end bolt for attachment to the coupling; and to provide a form tie of this kind wherein the couplings i may beloosened from the -concrete before re- -moval of the forms without alteringthe length of the form tie. i Illustrative embodiments of thisinvention are shown in the accompanying drawing, wherein Figure 1 is a Vertical transverse section of a concrete wall to which one of the improved ties is applied. V I Fig. 2 is an enlarged aXial section of one end of the form tie shown in Fig. I, part of 'the form J being also shown.

Fig. 3` is a View similar to Fig. 2,'but showing a modified form of coupling nut. i

Figs. 4: and 5 are details, in elevation, showing two different types of clamps for use on the outer ends of the end bolts.

. In the Construction shown, the improved form tie is applied to thecustomary. type of wall form comprising side members 1, studs 2 and battens 3.

In the form shown, in Figs. 1 and 2, each of' the improved ties oomprises an intermediate tie rod i and a pair of end bolts 5 alined axially and detachably secured together by coupling nuts6.

The tie red 4 isshorter than the distance between the form sides 1 and the ends of the rod are threaded with the usual right-hand threads for engagement with corresponding threads on the nuts 6. This Construction permits'the nuts to be readily adjusted relative to the tie rod and to each other.

The outer ends of the bolts 5 may be provided with any one of various clamps to secure the form against spreading. In the Construction shown in Figs. 1, 2 and 3, the end clamps include washers 7 and nuts 8. The end clamp shown in Fig. 4 comprises a collar 9 embracing the bolt 0 and provided with a set screw 10 for looking the collar to the bolt.

The clamp illustrated in Fig. 5 includes a bearing plate 11 and wing nut 12.

Heads 13 are formed on the outer extremities 5 of the bolts 5 to permit the bolts to be gripped by a wrench. The inner extrenities of the bolts 5 are threaded withright-hand threads which engage corresponding right-hand threads in the couplings so that, by applying a wrench to the 0 heads 13, the end bolts may be properly adjusted i In the construction shown in Figs. 1 and 2, the coupling nuts serve as spacers for spacing the form sides 1 the required distance apart. r The coupling shown in Figs. 1 and 2 has a tapered body 14 and an integral shank 15, having a cen-' tral bore 16. The outer end of the body 14 forms an annular hearing face 17 for engaging the inner surface of the form 1 and the shank 15 is adapted to project through an opening 18 in the side member 1'.

The bore of the tapered body 14 is threaded with the custoznary right-hand threads 19 for engaging the tie rod 4 and the bore of the sshank 15 is also provided'with right-hand threads 20 for engaging the corresponding threads on the inner end of the bolt 5. A head 21 is formed on the outer end of the shank 15 to permit the lar in a11 respects to that shown in Figs. 1 and 2 except that the hearing face 17 is omitted and, therefore, the nut cannot serve as a spacer for the sides of the mold. With such a Construction, separate spacing means should be employed for securing the form sides against inward movement. The nut shown in Fig. 3 comprises a shank 22 having a bore which is provided with right-hand threads 23 at its inner end and righthand threads 24 at its outer end. The inner end of the shank, which is adapted to be embedded in the concrete, is tapered and its outer end is provided with a head 25 for the application of a wrench.

In operation, the tie rod and end bolts are supported on the form in the manner illustrated in Fig. 1 during the pouring of the concrete. Before the concrete has compeltely set and While the form sections are still in place, the coupling nuts are slightly loosened from the concrete by applying a wrench to the heads 21 or 25. With the construction shown in Fig. 3, the couplng nuts may be completely removed from the concrete before removal of the form but, with the Construction shown in Figs. 1 and 2, in which the coupling nuts serve as spacers, it is necessary to dismantle the form before removing the ooupling nuts. With the Construction illustrated in Fig. 3, the couplng nuts may be rotated in either direction while the parts are assembled, Without in any degree expanding or contracting the form tie. This feature is of great advantage in the Construction of concrete walls because it permits the couplings to be loosened from the concrete without removing 2 or loosening the form.

invention has been herein shown and described, it i will be understood that certain details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims:

I claim:

1. The combination with a wall form having a side member, of a form tie comprising a tie rod and an end bolt alined axially, form clamping means on the outer end of said end bolt, and a coupling unit extending through said form side member and comprising a shank 'having a axial bore for receiving the adjacent ends of said rod and bolt, one end of said shank having a polygonal head projecting outwardly beyond said side member to permit the application of a wrench for loosening said coupling nut without disturbing said form side.

2. The eombination with a wall form having a side member, of a form tie comprising a tie rod and an end bolt alined axially, form clamping means on the oute' end of said end bolt, and a coupling nut threaded on the adjacent ends of said tie rod and end bolt, the threads being arranged to permit rotation of said coupling nut without altering the length of the form tie, one end of said coupling nut projecting outwardly beyond said form side member to form a head for receiving a Wrench whereby said coupling nut may be shifted outwardly relative' to said 'rod without disturbing the form.

LAWRENCE H. UMBACH. 

